The event you are referring to is a general call for the public. My understanding is that the Talons Challenge started and is still primarily a function of the ski school. You have to hire an instructor, then complete the runs. I don't believe you have to do them on one day, unlike the general call for the public event. The payoff is you get your name displayed in the lodge. You may get some swag as well, but not sure about that as I've only done the public event (4 times).
December may be a bit early to do the Talons Challenge, as the Birds of Prey runs are pretty steep and need lots of snow before they open them. Last year, the number of folk and the sparcity of snow made the event in mid January a rock-fest.
It's a good challege. 23k+ of skiing in a day, particularly the long big bump runs, certainly is enough to give most folk a physical workout.
It also appears that this year they public event is being delayed from it's usual mid-to-late-January date to late February. That's likely due to the number of folk who show up and the impact they have on the cover.